fix: evaluate property default initializers via AST instead of vm2

api.md

@@ -691,6 +691,23 @@ class MyObject {
 ```
 
 
+## [default-properties-initializer](./test/programs/default-properties-initializer)
+
+```ts
+export class MyObject {
+    varString: string = "foo";
+    varSingleQuoted: string = 'bar';
+    varNumber: number = 123;
+    varFloat: number = 3.21;
+    varNegative: number = -5;
+    varBoolean: boolean = true;
+    varNull: null = null;
+    varArray: number[] = [1, 2, 3];
+    varStringArray: string[] = ["a", "b"];
+}
+```
+
+
 ## [enums-compiled-compute](./test/programs/enums-compiled-compute)
 
 ```ts

package.json

@@ -48,7 +48,6 @@
     "safe-stable-stringify": "^2.5.0",
     "ts-node": "^10.9.2",
     "typescript": "~5.9.3",
-    "vm2": "^3.11.3",
     "yargs": "^18.0.0"
   },
   "devDependencies": {

test/programs/default-properties-initializer/main.ts

@@ -0,0 +1,11 @@
+export class MyObject {
+    varString: string = "foo";
+    varSingleQuoted: string = 'bar';
+    varNumber: number = 123;
+    varFloat: number = 3.21;
+    varNegative: number = -5;
+    varBoolean: boolean = true;
+    varNull: null = null;
+    varArray: number[] = [1, 2, 3];
+    varStringArray: string[] = ["a", "b"];
+}

test/programs/default-properties-initializer/schema.json

@@ -0,0 +1,67 @@
+{
+    "type": "object",
+    "properties": {
+        "varString": {
+            "type": "string",
+            "default": "foo"
+        },
+        "varSingleQuoted": {
+            "type": "string",
+            "default": "bar"
+        },
+        "varNumber": {
+            "type": "number",
+            "default": 123
+        },
+        "varFloat": {
+            "type": "number",
+            "default": 3.21
+        },
+        "varNegative": {
+            "type": "number",
+            "default": -5
+        },
+        "varBoolean": {
+            "type": "boolean",
+            "default": true
+        },
+        "varNull": {
+            "type": "null",
+            "default": null
+        },
+        "varArray": {
+            "type": "array",
+            "items": {
+                "type": "number"
+            },
+            "default": [
+                1,
+                2,
+                3
+            ]
+        },
+        "varStringArray": {
+            "type": "array",
+            "items": {
+                "type": "string"
+            },
+            "default": [
+                "a",
+                "b"
+            ]
+        }
+    },
+    "additionalProperties": false,
+    "required": [
+        "varArray",
+        "varBoolean",
+        "varFloat",
+        "varNegative",
+        "varNull",
+        "varNumber",
+        "varSingleQuoted",
+        "varString",
+        "varStringArray"
+    ],
+    "$schema": "http://json-schema.org/draft-07/schema#"
+}

test/schema.test.ts

@@ -423,6 +423,8 @@ describe("schema", () => {
 
         assertSchema("default-properties", "MyObject");
 
+        assertSchema("default-properties-initializer", "MyObject");
+
         // not supported yet #116
         // assertSchema("interface-extra-props", "MyObject");
 

typescript-json-schema.ts

@@ -9,8 +9,6 @@ export { Program, CompilerOptions, Symbol } from "typescript";
 
 export { ts };
 
-const { VM } = require("vm2");
-
 const REGEX_FILE_NAME_OR_SPACE = /(\bimport\(".*?"\)|".*?")\.| /g;
 const REGEX_TSCONFIG_NAME = /^.*\.json$/;
 const REGEX_TJS_JSDOC = /^-([\w]+)\s+(\S|\S[\s\S]*\S)\s*$/g;
@@ -250,6 +248,40 @@ function parseValue(symbol: ts.Symbol, key: string, value: string): any {
     }
 }
 
+/**
+ * Evaluate a property initializer expression to its literal value, without
+ * executing any code. Only the literal forms that can be represented in a JSON
+ * Schema `default` are supported: string, number, boolean, null and arrays of
+ * those. Returns `undefined` for anything that is not a supported literal.
+ */
+function evaluateLiteralInitializer(node: ts.Node): PrimitiveType | any[] | undefined {
+    if (ts.isStringLiteralLike(node)) {
+        return node.text;
+    } else if (ts.isNumericLiteral(node)) {
+        return Number(node.text);
+    } else if (ts.isPrefixUnaryExpression(node) && node.operator === ts.SyntaxKind.MinusToken) {
+        const operand = evaluateLiteralInitializer(node.operand);
+        return typeof operand === "number" ? -operand : undefined;
+    } else if (node.kind === ts.SyntaxKind.TrueKeyword) {
+        return true;
+    } else if (node.kind === ts.SyntaxKind.FalseKeyword) {
+        return false;
+    } else if (node.kind === ts.SyntaxKind.NullKeyword) {
+        return null;
+    } else if (ts.isArrayLiteralExpression(node)) {
+        const values: any[] = [];
+        for (const element of node.elements) {
+            const value = evaluateLiteralInitializer(element);
+            if (value === undefined) {
+                return undefined;
+            }
+            values.push(value);
+        }
+        return values;
+    }
+    return undefined;
+}
+
 function extractLiteralValue(typ: ts.Type): PrimitiveType | undefined {
     let str = (<ts.LiteralType>typ).value;
     if (str === undefined) {
@@ -866,22 +898,11 @@ export class JsonSchemaGenerator {
             } else if ((<any>initial).kind && (<any>initial).kind === ts.SyntaxKind.NoSubstitutionTemplateLiteral) {
                 definition.default = initial.getText();
             } else {
-                try {
-                    const vm = new VM();
-                    const val = vm.run("sandboxvar=" + initial.getText()) as any;
-                    if (
-                        val === null ||
-                        typeof val === "string" ||
-                        typeof val === "number" ||
-                        typeof val === "boolean" ||
-                        Object.prototype.toString.call(val) === "[object Array]"
-                    ) {
-                        definition.default = val;
-                    } else if (val) {
-                        console.warn("unknown initializer for property " + propertyName + ": " + val);
-                    }
-                } catch (e) {
-                    console.warn("exception evaluating initializer for property " + propertyName);
+                const val = evaluateLiteralInitializer(initial);
+                if (val !== undefined) {
+                    definition.default = val;
+                } else {
+                    console.warn("unknown initializer for property " + propertyName + ": " + initial.getText());
                 }
             }
         }

yarn.lock

@@ -108,14 +108,14 @@
   dependencies:
     undici-types "~7.16.0"
 
-acorn-walk@^8.1.1, acorn-walk@^8.3.4:
+acorn-walk@^8.1.1:
   version "8.3.5"
   resolved "https://registry.npmjs.org/acorn-walk/-/acorn-walk-8.3.5.tgz#8a6b8ca8fc5b34685af15dabb44118663c296496"
   integrity sha512-HEHNfbars9v4pgpW6SO1KSPkfoS0xVOM/9UzkJltjlsHZmJasxg8aXkuZa7SMf8vKGIBhpUsPluQSqhJFCqebw==
   dependencies:
     acorn "^8.11.0"
 
-acorn@^8.11.0, acorn@^8.15.0, acorn@^8.4.1:
+acorn@^8.11.0, acorn@^8.4.1:
   version "8.16.0"
   resolved "https://registry.npmjs.org/acorn/-/acorn-8.16.0.tgz#4ce79c89be40afe7afe8f3adb902a1f1ce9ac08a"
   integrity sha512-UVJyE9MttOsBQIDKw1skb9nAwQuR5wuGD3+82K6JgJlm/Y+KI92oNsMNGZCYdDsVtRHSak0pcV5Dno5+4jh9sw==
@@ -1006,14 +1006,6 @@ v8-compile-cache-lib@^3.0.1:
   resolved "https://registry.npmjs.org/v8-compile-cache-lib/-/v8-compile-cache-lib-3.0.1.tgz#6336e8d71965cb3d35a1bbb7868445a7c05264bf"
   integrity sha512-wa7YjyUGfNZngI/vtK0UHAN+lgDCxBPCylVXGp0zu59Fz5aiGtNXaq3DhIov063MorB+VfufLh3JlF2KdTK3xg==
 
-vm2@^3.11.3:
-  version "3.11.3"
-  resolved "https://registry.yarnpkg.com/vm2/-/vm2-3.11.3.tgz#5323018a93ae2862c9d52b07b658ebb8d74903f0"
-  integrity sha512-DO1TTKuOc+veL11VNOvJwRab80mghFKE40Av3bl6pdXs11bdiDMuR73owy+dS2EsTZEvRUeBkkBuDVRjV/RgEw==
-  dependencies:
-    acorn "^8.15.0"
-    acorn-walk "^8.3.4"
-
 which@^2.0.1:
   version "2.0.2"
   resolved "https://registry.npmjs.org/which/-/which-2.0.2.tgz#7c6a8dd0a636a0327e10b59c9286eee93f3f51b1"